A 55-year-old man with a 3-day history of fever, confusion, and focal seizures. CSF analysis: glucose 45 mg/dL (serum 90), protein 120 mg/dL, WBC 120/μL with predominantly lymphocytes. CSF HSV-1 PCR is positive. EEG shows periodic lateralised epileptiform discharges (PLEDs) over the left temporal region. The preferred duration of IV acyclovir treatment is:
- A 7 days
- B 10 days
- C 14–21 days ✓
- D 28 days if immunocompromised
Correct answer: C. 14–21 days
Explanation
HSV encephalitis requires IV acyclovir 10 mg/kg every 8 hours for 14–21 days. The 21-day course is recommended for immunocompromised patients and those with severe disease or significant neurological deficit. Shorter courses (10–14 days) are associated with relapse and treatment failures. After IV therapy, some guidelines recommend oral valacyclovir suppression (6 months) to prevent relapse, particularly in anti-NMDAR encephalitis triggered by HSV. PLEDs over the temporal lobe are characteristic of HSV encephalitis on EEG.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.